Emulsion-polymerized addition polymers are prepared by the polymerization of ethylenically-unsaturated monomers using ionic- or free radical-initiated and propagated reactions. In most cases these reactions will not proceed to the point of 100% conversion of the ethylenically-unsaturated monomer to polymer within a reasonable time. Elimination of the residual monomer may be desirable due to odor, instability, or toxicity, for example, resulting from the residual monomer. Subsequent elimination of the remaining ethylenically-unsaturated monomer by conversion to polymer by methods such as, for example, heating for prolonged periods, with or without the addition of an ion- or a free radical-source; or physical removal of residual ethylenically-unsaturated monomer by methods such as, for example, vacuum stripping and steam sparging; or conversion to a less undesirable species such as, for example, conversion to a non-volatile adduct have all been disclosed in the past. However, concerns about the toxicity or odor of organic compounds in general, and of ethylenically-unsaturated monomers in particular, have lowered the level of residual ethylenically-unsaturated monomer which is acceptable in emulsion-polymerized addition polymers-levels which are frequently difficult and costly to achieve by conventional techniques. One category of ethylenically-unsaturated monomers is carboxylester monomers wherein at least one carboxylester grouping, --COOR, is present. In addition, ethylenically-unsaturated monomers may contain organic carboxylesters, i.e., compounds bearing at least one ester grouping which are not ethylenically-unsaturated, which persist in the emulsion-polymerized addition polymer. Further, polymerization adjuvants may introduce additional organic carboxylesters, i.e., compounds bearing at least one ester grouping but which may not be ethylenically-unsaturated monomers. Such compounds, too, may give rise to concerns about toxicity or odor. The method of reducing the organic carboxylester content of an emulsion-polymerized addition polymer of this invention by contacting the aqueous emulsion polymer with a carboxylesterase solves these problems.